Pennsylvania Statutes Title 52 P.S. Mines and Mining § 70-1126. Bonding

Where air (except compressed air blast lines) or water pipes parallel the grounded return of power circuits, the return shall be securely bonded to such pipes at frequent intervals to eliminate the possibility of a difference of potential between rails and pipes to prevent electrolysis of the pipes. The rail return shall be of sufficient capacity for the current used, independent of the capacity of the pipes.